title: Reliability of the plaque assay to determine the sensitivity of Neisseria gonorrhoeae to the bactericidal activity of normal human serum.
abstract: A plaque assay for determination of the sensitivity of Neisseria gonorrhoeae to the complement-dependent bactericidal activity of normal human serum was evaluated. The method was found to be rapid and easy to perform. All strains, which gave a positive result by the plaque assay, were serum-sensitive in a quantitative assay, whereas only 78% of strains giving negative results by the plaque assay were true serum-resistant. The growth of a few gonococcal strains was inhibited, i.e. formed plaques, after exposure to genuine as well as to heat-inactivated normal human serum.
mesh_terms: D001431:Bacteriological Techniques; D001770:Blood Bactericidal Activity; D003165:Complement System Proteins / Q000502:physiology; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000254:growth & development / Q000276:immunology*
chemical_list: D003165:Complement System Proteins